EMC Annual Review:CPC’s Forecasts

2007

Edward O’LenicChief, Operations Branch

NOAA-NWS-Climate Prediction CenterDecember 12, 2007

Top 20 CPC Web Products – Nov 20071.) CPC Home page (150,730 hits) 2.) 6-10 Day Outlook (126,958) 3.) 8-14 Day Outlook (119,752) 4.) U.S. Hazards Assessment (58,890) 5.) ENSO Evolution, Status.....(PDF) (52,864) 6.) 90-Day Outlook (46,558) 7.) Forecasts & Outlooks Home page (45,625) 8.) 6-10 Day Outlook (PMD) (38,491) 9.) 30-Day Outlook (32,109)

10.) UV Index Forecast (text version) (31,487) 11.) ENSO Diagnostic Discussion (31,011) 12.) 30-Day Outlook (Lead 01) (29,214) 13.) Color Seasonal Outlook (multiple images) (27,224) 14.) Seasonal Drought Outlook (26,120) 15.) U.S. Daily Data (text) (20,957) 16.) 30-Day Outlook (Lead 02) (18,993) 17.) ENSO Home page (18,506) 18.) Seasonal Drought Assessment (14,736) 19.) Atlantic Hurricane Outlook (13,030) 20.) 90-Day Outlook (fxus05, text) (13,005)

Top 20 CPC Web Products – Nov 20071.) CPC Home page (150,730 hits)2.) 6-10 Day Outlook (126,958) 3.) 8-14 Day Outlook (119,752) 4.) U.S. Hazards Assessment (58,890) 5.) ENSO Evolution, Status.....(PDF) (52,864)6.) 90-Day Outlook (46,558) 7.) Forecasts & Outlooks Home page (45,625) 8.) 6-10 Day Outlook (PMD) (38,491) 9.) 30-Day Outlook (32,109)

10.) UV Index Forecast (text version) (31,487) 11.) ENSO Diagnostic Discussion (31,011) 12.) 30-Day Outlook (Lead 01) (29,214) 13.) Color Seasonal Outlook (multiple images) (27,224)14.) Seasonal Drought Outlook (26,120) 15.) U.S. Daily Data (text) (20,957) 16.) 30-Day Outlook (Lead 02) (18,993) 17.) ENSO Home page (18,506) 18.) Seasonal Drought Assessment (14,736) 19.) Atlantic Hurricane Outlook (13,030) 20.) 90-Day Outlook (fxus05, text) (13,005)

Outline• Atlantic Tropical Storm Outlook• U.S. Seasonal Drought Outlook• U.S. Hazards Assessment• Extended Range – 6-10, 8-14-Day • Intra-Seasonal Outlooks• 3-Month Outlooks

2007 Atlantic Tropical Storm Season

May 16 Forecast

August 2Forecast

2007 Actual

AverageSeason

TropicalStorms

11

62

Hurricanes

MajorHurricanes

Obs.% Normal

13-17 13-16 14 -27

7-10 7-9 6 1003-5 3-5 2 100

2007 was close to average. After several successful forecasts, this is the second consecutive year in which the forecast’s

expectations were not met.

U.S. Seasonal Drought Outlook• DM is produced collaboratively each by

NOAA, USDA, NDMC.• Seasonal Drought Outlook is produced

monthly at CPC.• Outlook is zero-lead.• Describes expected changes to the DM,

based on CPC’s seasonal outlook.• Uses up-to-the-minute model forecasts, as

well as the 3-month P outlook.

% DO gridpoints correct minus % persistence gridpoints correct

Drought Outlook -- Forecast minus Persistence

-20

-10

0

10

20

30

40

50

60

Jul '03 Nov'03

Mar'04

Jul '04 Nov'04

Mar'05

Jul '05 Nov'05

Mar'06

Jul '06 Nov'06

Mar'07 Jul'07

Date of Forecast

Fore

cast

Les

s Pe

rsis

tenc

e

Skill MEAN Linear (Skill)

Average: 13 % better than climatology

U.S. Hazards Assessment

Observed Not observed

Forecast 2086

a

7306b

Not forecast 41753

c307685

d

CONTINGENCY TABLEHEAVY PRECIPITATION HAZARDS

2002-2007

Hit Rate, heavyPrecipitation events

= a/(a+c)=# hits/(# fcst and obs)= 0.05

False Alarm rate, heavyPrecipitation events

= b/(b+d)=# miss/(# all forecasts)= 0.02

Heavy precipitation is defined as the greater of the 95th percentile, or 1 inch per day.

Updated each Mon-Fri, using daily GFS forecasts of extreme events.

Bias, heavyPrecipitation events

= (a+b)(a+c)=# yes fcsts/(# yes obs)= 0.21

U.S. Hazards Assessment

Observed Not observed

Forecast 2086

a

7306b

Not forecast 41753

c307685

d

CONTINGENCY TABLEHEAVY PRECIPITATION HAZARDS

2002-2007

Heavy precipitation is defined as the greater of the 95th percentile, or 1 inch per day.

Updated each Mon-Fri, using daily GFS forecasts of extreme events.Needed: Calibrated extreme event forecast probabilities from the GEFS

Hit Rate, heavyPrecipitation events

= a/(a+c)=# hits/(# fcst and obs)= 0.05

False Alarm rate, heavyPrecipitation events

= b/(b+d)=# miss/(# all forecasts)= 0.02

Bias, heavyPrecipitation events

= (a+b)(a+c)=# yes fcsts/(# yes obs)= 0.21

NCEP- CPC Extended-Range (6-10-, 8-14-Days) Forecast Operations

OCEAN

ANALYSIS, RE-ANALYSIS

DYNAMICAL Models:

NCEP GFS, others… STATISTICAL

T, P TOOLS, CALIBRATION

OFFICIAL TEMPERATURE & PRECIPITATION

OUTLOOKS

Forecasters merge T, P tools subjectively

ATMOSPHERE

ANALYSIS, RE-ANALYSIS

Atmosphere forecasts

VERIFICATION

Objective 500-hPa Height forecast, from forecaster-

assigned weights

OFFICIAL 500 HPA HEIGHT AND

ANOMALY FORECAST

VERIFICATION

8-14-day (D+11) Forecast for Dec 19-25

ER Z-500 ACOfficial, GFS

Height forecasts are made by calculating a weighted average of GFS, ECMWF, Canadian models, with weights selected by the forecaster. GFS, Canadian, ECMWF are the choices. GFS is usually the major component. No subjective modifications are made to the weighted mean by the forecaster.

6-10

8-14

Calibration (Downscaling) is Extremely Important in Climate ForeCalibration (Downscaling) is Extremely Important in Climate Forecastingcasting

Ensemble Regression Assembles an Optimal Distribution Based on Spread of the Members and on

the Skill of the Forecast system.

Official ER Forecast Heidke SS, 6-10-/8-14-Day T, PMonthly Means, Dec 2006-Nov 2007

-20

-10

0

10

20

30

40

50

60

200612 200701 200702 200703 200704 200705 200706 200707 200708 200709 200710 200711

Month

% Im

prov

emen

t Ove

r Ran

dom

610 T

814 T

610 P

814 P

mean=38.2

mean=29.2

mean=15.5

mean=4.6

DEC2006

NOV2007

Daily 6-10- and 8-14-day Heat Index (Wind Chill) Outlooks are prepared by calculating the heatindex (wind chill) from GFS 2-meter T, RH (GFS 2-meter T, 10-meter wind) and then calibrating

using 45 days of observed heat index (wind chill) and GFS forecasts.

Probability theminimum wind chill will be in the below -10F.

May Oct

Oct Apr

WARM SEASON

COLD SEASON

NCEP- CPC Intra-Seasonal Forecast Operations

OCEAN

ANALYSIS, RE-ANALYSIS

DYNAMICAL Models:

NCEP GEFSSTATISTICAL T, P TOOLS

EXPERIMENTAL GLOBAL HAZARDS

MAP AND TEXT

Forecasters merge T, P tools subjectively

ATMOSPHERE

ANALYSIS, RE-ANALYSIS

Atmosphere forecasts

VERIFICATION

GEFS projected onto MJO CEOF modes

VERIFICATION

Experimental MJO ForecastsDaily GEFS

forecasts are projected onto modes resulting from a CEOF analysis of U200, U850, OLR.

GEFS Based MJO Forecast Tool

Current GEFS MJO index forecast

Recent MJO Event Verification

Used as part of weekly CPC MJO weekly update and hazard assessment products. Recently, GEFS MJO forecasts have been remarkably accurate. Forecast (green) begun December 3,

2007

Forecast (green) begun Nov 26, 2007. Others are observations.

GFSCFS

Verification, January-September, 2007The success of the GEFS in forecasting the latest MJO

reflects, in part, the impact of the information in the initialization. Ensemble Regression can be applied to the ensemble members.

Global Tropics Hazards/Benefits AssessmentWeekly MJO Update

NCEP- CPC Seasonal Forecast Operations

OCEAN

ANALYSIS, RE-ANALYSIS

DYNAMICAL MODEL TOOLS:

NCEP CFS, OTHERS …

STATISTICAL SST MODEL

TOOLS

STATISTICAL T, P MODEL

TOOLS

OBJECTIVE CONSOLIDATION BASED ON KNOWN SKILL OF FORECAST TOOLS (ensemble

regression)

SUBJECTIVE FORMULATION OF FORECAST MAPS

OBJECTIVE CONSOLIDATION BASED ON KNOWN SKILL OF TOOLS (ensemble regression)

ATMOSPHERE

ANALYSIS, RE-ANALYSIS

OFFICIAL SST FCST

Atmosphere

forecastsO

cean

fore

cast

s

OFFICIAL TEMPERATURE & PRECIPITATION OUTLOOKS

VERIFICATION

VERIFICATION

CRPS Skill

00.10.20.30.40.50.6

1 2 3 4 5 6

Lead (Months)

CR

PSS

CCA CA MKV CFS-Uncal CFS ALL

1995-2006Ensemble Regression Calibration Improves CFS SST Forecasts

CFS Nino 3.4 SST Forecasts 1995-2006

CFS & Official SST Forecasts

Heidke Skill Score 48 Month Running Mean Official 3-month T OutlooksNDJ 1998-SON 2007

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

Dec-98

Mar-99

Jun-99

Sep-99Dec-9

9Mar-0

0Ju

n-00Sep-00Dec-0

0Mar-0

1Ju

n-01Sep-01Dec-0

1Mar-0

2Ju

n-02Sep-02Dec-0

2Mar-0

3Ju

n-03Sep-03Dec-0

3Mar-0

4Ju

n-04Sep-04Dec-0

4Mar-0

5Ju

n-05Sep-05Dec-0

5Mar-0

6Ju

n-06Sep-06Dec-0

6Mar-0

7Ju

n-07Sep-07

Ending Month of 3-month Forecast

% Im

prov

emen

t ove

r ran

dom

GPRA GPRA GOAL

SON 2005:First forecast made using

the consolidation

Regional % Improvement by the ½-month Lead 3-Month Mean Temperature Forecast over Climatology

Official and Consolidation – 1995-2004

Difference: Official minus Consolidation

Prospects for the (Present &) Future

• Probabilistic Extreme Events forecasts (U.S. Hazards Assessment)• Disaggregated ½-Month Lead 3-Month Temperature Outlooks• Operational MJO Outlooks for the Tropics• CPC Forecasts and Climatologies on NDFD available to users via SOAP• Gridded 3-Month Outlooks for the Pacific and Caribbean• Expansion of Ensemble Regression Calibration to Alaska 3-Month Outlooks• Probability of Exceedance for ER forecasts